Double diaphragm transmitter



April 12, 1927.

v 1,624,353 c. R. MooRE ET Ax.

DOUBLE DIAPHRAGM TnANsuITTER Filed Julyso. 1924 fy/f -50 on the frontportion Patented Apaf 12, 1927.

f UNITED STATES PATENT OFFICE.

CHARLES RUBY MOORE, OF MAPLEWOOD, NEW JERSEY, AND JOHN H. HAYWARD, F NEWYORK, N. Y., ABSIGNORS TO WESTERN ELECTRIC COMPANY, INCORIORATED, QF NEWYORK, N, Y., A CORPORATION OF NEW YORK.

DOUBLE DIAPHRAGI TRANSMITTER.

Application led July 80, 1924. Serial No. 729,010.

This4 invention relates to telephone e uipment and particularly tolinemens telep instruments.

Heretofore such equipment has consisted 5 ofwa handset, that-is to sayan instrument wherein the transmitter and receiver are mounted on acommon handle. In using such a handset while talking, the lineman has touse one of his hands to d the hand'- set. Therefore, he has only onehand free for testing, etc.

The object of the presentinvention is to provide a light weighttransmitter for 11nemen to fasten .on the coat or other ieee of l5clothing and whenl used with a hear t will replace the `customaryhandset which must be held inthe hand, leaving lonly-one hand free fortesting, etc. t

In accordance with this invention, .a

rugged transmitter is provided. .which will withstand the hard usagesuch instruments get in service, and which at the sometime is sensitiveand light' in weightso thatlt may be attached by a clip tothe linemanscoat or other vpiece of clothin and .in that position will take u thesoun of his voice very readil the lineman being proyided withan or naryhead' receiver for listen- `3o fore particularly the transmitterconsists of a casing of very light material, for ex ample, aluminum,formed of preferably two etrical. parts which carry a mu tiple iaphragmcarbon button, and .when .joined an fastened together vprovide a housingfor the transmitter button with air passages leading from the o n end ofthe'rcasing to the diaphragme, an' make up a symmetrical and 'ad`exterior contour.

Other features of the invention vanta'ges will appear from the followingdescriptlon and by the appended claim, refer- ,ence being had to theaccompanying ,draw ing' in which Figv 1 isan enlarged sectional view ofthe transmitter taken approximately on -line 1-1 of the Fig. 3. Fig. 2is a sideview of the transmitter with the casing partially cut away'andFig. 3 is a top. view of the transmitter showin o? the mouthpiece.-yrreference characters refer to similar 'parts throughout thedescription.

`The telephone transmitter of this iuuveii-4v the protecting tionconsstsof a mouthpiece which is prefreceivethe hubs of their respectively assotciated discs 17 and 18 provided for insulat@ ing the transmitter buttonfrom the mouthpiece parts 10 and 11, respectivel The transmitter buttonT consists of two electrodes 19 and 20 which are fastened together bymeans of a shoulder ring 21 screwed on electrode 19. An insulating disc23,. dis sed between theshoulder portion 22 of ring21 and electrode 20is provided for'insvulating the electrodes from eachother. An insulatingdisc or barrier 24 interposed one erably formed by two similarly shapedparts 55 between electrodes 19 and 20, isprovided for insulating theelectrodes and tolform a path across which the current must pass.

Each electrode;A` 19 and 20, is associated with a conical'shapeddiahragm25 ande26 which have their apexes position and'each in contactwith the carbon 'granules as shown in 1. On opposite sides of eachdiaphragm, here are provided a plurality of daniil aper discs 27 genng Perallj known asr book damping. The

screens 36 and 37 are provided for protectt oo fall into the air pasingthe daphragms 25 and 26 from dust particles which may sages in theshellsv13 and 14. The screens 36, 37 the diaphragms 25 and 26, to therwith the aper discs 27 are held in adlusted position y meansv of anges28 and 29, which are screwed in the electrodes 19 and 20 respectively.The lflanges 28 and 29tare each provide with ahiibportion adapted to tinto their respectively associated apertures in the insulat' cooperatetherewith or Y- holding mitter button 31-in position. g

The spring rings 30 and 31 are dispose between electrodes 19 and 20`andthe insulat ing discs 17 and 18. Theserings are pro the transand .thespring rings 30 and v e d.

vided for holding the transmitter button against movement in the housingand to protect the button from the usual accidental shocks and j'arswhile in use. The rings 30 and 3l are each provided with a lug 32 and 33upon which the Wire terminals 34 and 35 may he attached in anyconvenient manner. A protecting screen 38 is mounted on the frontportion of the transmitter mouthpiece and is held securely thereon bymeans of screws 40. On one side of the mouthpiece there is mounted apair of pincers 39 shown in Figs. 2 and 2l which are adapted forsecuring the transmitter to the belt or coat ot the lineman. Thetransmitter of this invention is also Well adapted for use With deal.sets or wherever a very sensitive transmitter is required.

lllhat is claimed is:

A telephone transmitter comprising a 20 holding the microphone againstlateral l movement in said housing and for securing the conducting Wiresof said transmitter.

In witness whereof, we hereunto subscribe our names this 22 day of July,A. D. 1924.

CHARLES R. MOORE. JOHN M. HAYWARD.

